Grafted polymers are known in the art. By way of illustration, U.S. Pat. No. 3,418,354 discloses siloxane-polyalkylene oxide graft copolymers made using siloxanes having at least two olefinic groups. The copolymers of the U.S. Pat. No. 3,418,354 are disclosed therein as being useful as surfactants.
As another illustration, U.S. Pat. No. 4,146,488 discloses metal lubricant compositions containing poly(oxyalkylene) compounds grafted with about 3 to 15% by weight of acrylic or methacrylic acid followed by neutralization with alkanolamine. That patent discloses at column 7, lines 50 to 68 and column 8, lines 1 to 15, that such a polymer, when used in aqueous monoethanolamine borate solution is effective in providing cast iron corrosion protection.
Co-pending U.S. application Ser. No. 335,614 (now U.S. Pat. No. 4,392,972) discloses that aqueous and/or alcohol solutions of a certain class of such acrylic acid graft polymers have a particularly beneficial effect in inhibiting aluminum corrosion, most notably with respect to an aggressive form of aluminum corrosion, namely that which occurs at "heat rejecting" aluminum surfaces such as solar panels and the cylinder heads and blocks of internal combustion engines. This finding is particularly significant in view of the fact that there is increasing reliance on the use of aluminum components in the manufacture of heat transfer systems, such as those in solar and automotive systems, as part of an overall trend toward weight reduction.
Further improvements in aluminum corrosion inhibitor above and beyond those shown for the above cited grafted polymers would be desirable.